Dental flask



A. HORA DENTAL FLASK Dec. 13, 1949 2 She'ets-Sheet l Filed Feb. 25, 1947Dec. 13, 1949 A. HORA 2,491,046

DENTAL FLASK Filed Feb. 25, 1947 2 Sheets-Sheet 2 2/ y /9 @J3 20 jhnwHora? W fmwff;

Patented Dec. 13, 1949 UNITED STATES PATENT OFFICE 2,491,046 DENTALFLASK Anna Hora, Cleveland, Ohiov Application February 25, 19457; SerialNo.v 730,676 l 3 Claims.

My invention relates to dental flasks for making dentures and moreparticularly to a novel construction thereof which facilitates assemblyand disassembly of the sections thereof and removal of the plasterinvestment and separation and removal thereof from the denture ofacrylic or methacrylate and teeth without cracking or checking of theformer or cracked or broken teeth.

With the asks at present in use it takes fifteen to twenty minutes topound them open with a hammer or other tool, and the dentures and stonemodel are left firm, with the stone hard set and unbroken, so thatdental technicians sometimes check and crack the dentures and one ormore teeth, thereby requiring resetting and replacing such teeth orremaking of the denture, causing hours of extra labor and cost, as wellas misfits.

My flask comprises upper and lower hinged sections and top and bottomlids or covers in the form of flat plates all of suitable metal, thehinged sections being held together or closed at their free edges andthe lids on the top and bottom, by readily disengaged resilient snapfasteners and the adjoined edges of the parts having registering pryslots or notches so that only a pry tool or screw driver is required toopen and close the flask sections without requiring hammering andleaving the teeth perfect.

Another object is to provide means to form the plaster investment forthe denture in the mold or ask, in segments, preferably ve, which arejoined together by thin portions at recesses therein cut away nearly tothe imbedded denture so that the segments may be readily separated andbroken away from the denture in addition to easy separation of theplaster from the flask sections by lining the latter with tin foilcovering, the parting line or joint between the upper and lower sectionsso that the plaster and denture may be easily and quickly taken out ofAthe flask when opened, so that to open it is to clean it, therebyovercoming the objections, diiiiculties and cumbersome methods generallyemployed in addition to requiring no hammering, less plaster with asaving of at least making it much easier to remove the plaster from thedenture than where the plaster is thick all around, safer, and avoidingbreaking, checking and cracking of the acrylic or teeth as pulling theteeth out or loose.

The invention also comprehends the provision of curved tapered partingfins or partitions extending in from the walls of the iiask sections ina direction away from the hinge or pivot thereof adapted to formsegmental recesses in the edge of the plaster to points in closeproximity to the denture and a similar fin or partition iriserted inopposed recesses in the sections where' they come together opposite thehinge joint, so that when the sections are swung open, Vthey easily moveout of the recesses in the plaster; slip or release therefrom withoutresistance due to the movement thereof in the same arc traveled by thesections on the pivots or hinge pins so that there is no tendency tocrack the denture', and no ba'ckdraftkorundercut to resist opening'thereby facilitating removal 0f the plaster with the denture therein andseparation of the plaster from the denture after such removal and makingthe device 50% quicker, easier and safer to use.

The present invention consists in the novel form, jcombinationi andarrangement of parts hereinafter more fully'described, shown in thevaccompanyingdrawing, and claimed.

' In the drawings: Figure 1 is a front elevation of the improvedl flask0f my invention. V

Figure 2 is a side elevation thereof.

Figure 3 is a rear elevation. Figure 4 is a sectional view taken on theline 4 -4 of Figure '1. Vg Figure 5 is a perspective view of the plasterinvestment with a denture therein removed from the flask, and Figure Gis'a fragmentary section taken on the line 6-6 of Figure '1.

Referring to thedrawings in detail, the novel easy out dental flask isshown as comprising upper and lower lateral sections IQ and IIcomprising side walls each having substantially concentric portions I2and obtusely curved portions IS oflarger. arcs with relatively flat sideportions I4 therebetween. The ends of the portions I2 are provided withinteriitting apertured ears I5 and lugs I5 hinged or pivoted together bymeans of pivot pins or pintles l'I separately pivoting the parts of eachsection to swing together or apartl as shown by the arcs X as seen inFigure 4. y

, The free ends of the side walls are designed to abut in closedrelation and are detachably held together bysnap fasteners I8. For thispurpose, the sections'at the outerfaces of their portions I3 in spacedrelation to their abutting ends, are provided with slightly oppositelyundercut tapered notches I9 into which inwardly extending slightlyoppositely curved or inwardly converging lugs 20 at the ends of the barsof the snap fasteners I8, which may be slightly resilient, are adaptedto frictionally engage. One end of each bar is also provided with aprojection 2I spaced from the outer beveled face of a notch, beneathwhich a screw driver or similar instrument is adapted to be engaged topry oir or dislodge the fasteners to permit the sections to be opened.

Sections I and II are fitted together at coacting edges and the open topand bottom are closed by lids or covers 22 and 23 detachably held inpositron. For this purpose, the opposed relatively at portions I4 andlids 22 and 23 are provided on their outer faces and edges withtransverse aligned grooves 24 in which guide bars 25 and 26 are securedas by screws 21 engaged in, threaded apertures in the wall portions I4.The upper bars 25 are longer than the lower, bars 2,@ and overlap thelower section II partially and.A have two securing screws attach-ingtothe upper section IU, while a single screw attaches thelower bar. Theends of the grooves 24 at lids or covers 22 and 23 are inset or beveledas at, 28 frictionally engaged by angularly projecting end lugs 29 whichmay be beveled as shown. These bars 25 and, 26 hold the flask sectionsand lids in register; and may be removed by removing or loosening thescrews and pried loose by a screw driver at undercut inset or beveledgroove ends 28. In addition, one or opposite sidesY I4 adjacent grooves24 may be providedwith registering tapered pry slots or notches 3U atthe coacting faces of the sections and edges of the lids or covers, forthe insertion and twist of ascrew driver or the like to separatethesections and lids to take theflaskV apart.

The walls of the flask sections are provided withA curved taperedparting fins or partitions 3| extending in from the walls of the flasksections in a A direction away from the hinge or pivot thereof or curved in arcs so as to swing or move along the arcs X swung by thesections when opened and closed. Two spaced insl 3l areA provided oneach side at portions I3, and in addition, a fifthl n or partition. 32is removably inserted in coacting corner recesses 33 in the innerfacesand abutting ends of the sections.r The fin32'is tapered at itsinner end and extends toward the pivot I1 to ferm two segments S theplaster investment P between the denture D, the adjacent fins 3I andportions I3 and I4. The 3Ijform three segmentsT therebetween, so thatthere are, ve segments in all joined by thin portions Yf at recesses B.formed by said ns extending in from the edge of the plaster. By reasonof these thinor fragile portions Y, the segments maybe readily separatedand broken away from theY denture. TheA pivot ears and lugs I5 and I6,`also form arecess U in the plaster. When the snap fasteners I8 Vareremoved, the tapered o r wedge partition 3,21mayV bereadily removed fromthefplasten besides being released from the abutting endsof the sectionswhen separated, and since the @ask is lined with foil and the curved 3|move in the arcs X theV l same as the sections I0 and II after removingthe lids, the fins 3 I will readily move, pull out,slip or withdraw fromthe plaster investment leaving the recesses and thin frangible portionsto permit the plaster to be easily broken away from the denture, withouthammering', breaking, checking or cracking of the denture andteeth. Asthe GIL upper and lower flask sections are the same, the stone modelwith the plaster below and the dentures with plaster above are out withthe twist of a screw driver. The plaster and denture are easily takenout of the flask or the latter easily removed in a few minutes safelyWithout mistakes and cracked acrylic or broken teeth. The flask willlast indefinitely in service as it does not require hammering or severetreatment to use it, and the plaster recesses produced by the finsrequire less plaster with ve integral segments easily broken away fromthe dentures, leaving very little plaster to dispose of.

IY claim:

1'. In a dental flask, a body section composed of two4v similar partshingedly connected at corresponding ends and each having an inwardlyprojecting and tapered investment dividing ns, said finsbeing spacedfrom and cured in a direction concentric with the hinge connectionbetween said parts, said fins being of the same vertical Width as saidbody section.

2. In a dental flask, a body section composed` of two similar partshingedly connected at corresponding'e'nds and having spaced inwardlyprojecting and tapered investment dividing iins which are spaced from,4and curved in a direction concentric with the hinge connection betweensaid parts, said parts having mating recesses. in the inner corners oftheir other ends, a removable investment dividing iin having its outerportion4 leived in saidrecesses, and means releasably securing saidother ends together and' retainingV the outer portion of said removablefin in said' recesses.

3. A dental flask, comprising an open-ended' body composed of twosimilar superimposed body sections, each body section comprising twosimilar parts hingedly connected together at corresponding ends and4releasably secured together at their other ends, said parts havingallned transverse.

body section4 and having corresponding ends-A thereof engagingthe other`cover to secure it in place..

ANNA HORA.

REFERENCES CITED The followinglreferences are of recordinthe le of thispatent:

UNITED STATES IEA'I'EN'I'S` Number Name Datev4 246,234 Starr Aug. 23,1881 684,253 Houston v Oct. 8, 19,01V

2,030,524 Lambert Feb. 11, 1936 2,159,437 Kirby May 23, 1939. 2,328,285MacDougall Aug. 31, 1943

